Humidifier



FIG. 1 is a top perspective view of a humidifier showing my new design;

FIG. 2 is a front side elevation view thereof;

FIG. 3 is a top side elevation view thereof;

FIG. 4 is a back side elevation view thereof; and,

FIG. 5 is a left side elevation view thereof, the right side being a mirror image. 

The ornamental design for a humidifier, as shown and described. 